The invention relates to a display device, especially for a motor vehicle, wherein the image displayed can be varied.
Display devices are known, for example for displaying the digital street maps of a navigation system. Here the display unit, which is designed for example as an LCD or a monitor, is operated by means of a display controller, which continuously changes the representation on the display unit as a function of current position. Moreover, the display controller changes the image format on the display unit as necessary depending on commands entered through input control. Since the available installation space is limited, especially in motor vehicles, repeated efforts have been made to allocate multiple convenience systems to an existing display device, so that the information from various systems can be displayed as needed. Using a menu, for example, the user can select a system whose information is displayed generally in the form of another menu. As is known from the computer field the information and input options that are offered are organized hierarchically in sub-menus. A disadvantage of the known display devices is that the user can easily lose track of where he is currently located in the menu system. Another disadvantage arises when the user wishes to switch between individual displays, since the superposition of multiple menus known from the computer field can be used only to a limited extent because of the size of the display unit.
It is an object of the invention to provide an improved display system for providing alternate display images.
As a result of a movable image format on the display unit, or a movable display unit with a visual field delimitation, where the entire display unit can be used to present information, the display device can be associated with several systems at once, where only the information for one system is presented on the display unit at any one time.
The movable display device can be moved either directly through a manual mechanical transmission of force and/or indirectly through a control unit. In the case of indirect movement, the input commands that are entered via the control unit are converted into control signals for actuators, for example for stepper motors.
In a preferred embodiment, the display unit is designed as a hemispherical or spherical shell, by which means a large display area on a spherical surface is achieved in a small installation space.
In another preferred embodiment, a stop is associated with the display unit for each direction of motion, so that the display unit can be returned to a base setting by means of a spring return device.
The control unit is preferably designed as a trackball and/or as a joystick, where motion control of the display unit, in the form of a hemispherical or spherical shell, is very simple, especially with a trackball. In principle, the input unit can also be designed as a pushbutton or rocker switch.
The display unit is preferably designed as a touch screen, whose touch-sensitive fields form a control unit that can be used to input movement commands as well as data and control commands.
In a further preferred embodiment, the display device is integrated into a steering device of a motor vehicle, so that a vehicle driver has the display unit in his direct field of view. Depending on the form of the display unit, it may be necessary to modify the steering device to accommodate the display unit for this purpose. It is advantageous for this purpose to design the steering device as a steer-by-wire system. The advantage of steer-by-wire systems, as for example per U.S. Pat. No. 5,237,441 or DE 42 15 630 A1, is that the centrally located steering linkage is eliminated, which significantly simplifies the integration of spherical display units in particular.
The invention is described in detail below using example embodiments.